Chain-adjusting device



March 10, 1931. A F. c. THOMPSON 08 CHAIN ADJUSTING DEVICE Filed Jan. 26, 1926 2 Sheets-Sheet 1 March 10, 1931. THOMPSON 1,795,908

CHAIN ADJUSTING DEVICE Filed Jan. 26, 1926 2 Sheets-Sheet 2 25 my invention.

Patented Mar. 10, 1931 .FRED O. THOMPSON, OF -DETROI'I' MICHIGAN, ASSTGNOR T IVYEQRSE CHAIN CGMPANY,

OI ITHACA, NEW YORK, A CORPORATION 01 NEW! YORK 'CHAIN-ADJUQ'IING DEVICE This invention relates to adjusting devices and is particularly useful in connection with front end drives for automobiles.

One of the primary objects of this inven eliminated.

.How the forego1ng,together with such other ob ects and advantages as may hereinafter appear, or are incident to my invention, are

realized, is illustrated in preferred form in the accompanying drawings, wherein Fig. 1 is a diagrammatic front elevation of a typical front end layout of an automobile; Fig. 2 is an enlarged sectional view of the preferred form of my device;

Fig. 3 is a section taken on the line 83 of .Fig'. 2, and

Fig. 4: is a face view showing a detail of :The front end layout shown in'Fiml is of the usualtriangular arrangement and comprises a crank shaft sprocket 5, an accessory shaft sprocket 6 and a cam shaft sprocket driven in clockwise direction by the chain 8. The adjusting device indicated as a whole by the reference letter A is shown associated with the accessory'shaft 6a and its sprocket 6 which is the preferred arrangement; although it is to be understood that the device may be associated with a stub shaft and idler sprocket.

Referring now more particularly to Fig. 2,

it will be seen that I have shown a'bearing 9 detachably mountedin the frame 10, which extension 15 is rotatably mounted the co- Another object of this invention is the pro-v 10 v1s1on of a device of the character described. 1n whlchv the danger of overad ustment is Applicationfiled January 26,1926. Serial No. 83,791.

centric 16 on which eccentric thesprocket' i Y wheel 6 over which the chain passes is rotatably mounted. The eccentric'lfi is, provided with a circular flanged portion 17 which is coaxial with the shaft 6a, and the periphery I of which is provided withgear teeth 18.. In

thisinstance the teeth 18 are shown as extending somewhat fover around the periphery which is approximately the working range of the eccentric. 9

As a means for moving the eccentric in order to take up the slack in the chain, 1 have provided a spring actuated or rotated gear 19 mounted to mesh with the gear. teeth 18 of the eccentric flange 17; said'gear being mounted on the shaft 20 whlch is secured to .the nut 25 In this connection it is pointed out that the spring 21 is wound in a direction to cause the gear 19 to rotate 1n a clockwise direction.

' As thus" far described the device operates as follows The gear 19 under the influence of the spring tends to rotate in a clockwise direction which tends to cause the eccentric16 to rotate in a counterclockwise direction, by virtue of its geared association with. the gear 19, so that the eccentric through themedium of the gear 6 operates on the chain to take out the slack. a

When the chain is running there-is a tendency for the pull of the chain on the sprocket to cause the eccentricto be moved 'baclrwhich; of course, would againdevelop slack unless provision is made to prevent this. In order to prevent such action I have provided a latch device for holding the eccentric in'its positions of adjustment with which device I have associated means adapted to yield within certain. limits to prevent the chain from being overadjusted as will now, appear.

In this instance the latch device comprises two spring pressedv latches or plungers 26 carried on the eccentric and adapted to snap into thenotches 27 in the washer or plate V lun ers are so saaced with relation to the its positions of adjustment by means of t cushioned spring and slotconnection and notches as to give a fine adjustment with relatively coarse notches. As the eccentric is moved the plungers snap into registering if 1. l 1, 1 J L L'L notches so M12111 any oackwarc thrusts on the eccentric, such as are caused bythe running pull of the chain, are transn to the washer 28 moving it in the direction or the arrow shown in Fig. such movement howev r being cushioned by the spring 29 located in the slot 30 in the washer 28, one end of said spring engaging the slot 30 at land the other nd engaging the pin 32 which is b '9 l 't 'll" sccuiec. in cat eaimg i ius 1 .vi oe seen that the eccentric is yieldin'gly held in that danger of over djustmen nated because the ruin 'is thus utilized to counteract a certain amount of the forces movin the eccentc. The

1 amount of movement which may be given to the washer in this direction is determined by the slot or notch 33 in the washer and the pin 34 in'the bearing 9.

Reverting now to Fig. 2 it will be seen that I have coupler. the sprocket wheel 6 to the shaft 6a by means of a suitable coupling device, for example an @ldham coupling B, one portion of which is here shown as formed directly on the sprocket wheel. This wheel and the otherparts of the coupling deviceare held in operative association by means of the springs of which any suitable number may be employed. In installations in which the sprocket wheel 6 is merely an idler and the shaft 666 a stub shaft the coupling device may be dispensed with and a nut and washer may be substituted therefor to hold the sprocket wheel and eccentric against displacement.

Lubricant may be suppliedto the various working parts of the device by means of a plurality of connected ports, annular passages and grooves,'tlie lubricant being supplied thereto by means of the pipe 36 as will be clearly seen upon inspection of 2..

The arrangement is one by virtue of which it is possible to decrease the overall length of the device making it particularly useful where available space is restricted.

I claim r 1. A tension for endless chains includingmeans normally acting on the chain to take up slack therein and means supplementing the aforesaid means to yieldingly hold the eccentric in positions of adjustment, together with means limiting the amountof yield.

2. A tension adjuster for endless chains including an. eccentrically mounted sprocket wheel over which the chainpasses, means for moving said wheel and its mounting into various positions of eccentricity to take up slack in the chain including a spring rotated gear having connection with the eccentric mounting.

3. A ten ion adjuster for endless chains incluoi eccentrically mounted sprocket wheel inovi tions of eccentricity to take up slack cludi a spring rotated gear 2 flb I I 0 having geared connection wit the eccentrlc 0 ier with means for yieldingly ho wheel and its mounting in posltions of adjustment. 7

A tension adyuster for endless chains inof said shaft and having a gear portion, a sprocket wheel rotatably mounted on said eccentric over whichrthe chain passes, and means for moving the eccentric to take up e chain including a spring rotated $111,); with the gear portion of said c. A tension adjuster for endless chains including a game, a shaft, a bearing forsaid shaft detachably secured tosaid frame, an eccentric mounted for rotation about the axis of shaft and having a gear portion, a sproc -et wheel rotatably mounted on said eccentric over which the chain passes, and means for moving the eccentric to take up slack in the chain including a spring rotated gear meshing with the gear portion of said eccentric.

6. A tension adjuster for endless chains including yieldable means normally operating on the chain in a directionto take up slack therein, and means preventing yield of the aforesaid means beyond a limited amount in a reverse direction including a stop member and a fixed support carrying said member.

7. A front end drive forautomobiles com.- prising in combination two or more sprocket wheels. chain passing over said wheels, a shaft for one of said wheels, a bearing for said shaft having an extension, an eccentric revoluble on. said extension, means normally tending to rotate said eccentric in a direction to shift said wheel to take up slack in the chain, m ans supplementing the aforesaid means to yieldingly hold the eccentric in positions of adjustment, and means limiting the amount of yield.

in testimon 1 whereof I have hereunto signed my name.

FRED C. THOMPSON. 

